Virtually impossible to close an account

Closed my account on 16 April 2022 in person at the Randpark Ridge branch. I signed documents to this effect and ensured that there were more than sufficient funds in the account to cover any expenses - in fact, the teller asked me to withdraw money from the account. 3 weeks later I find that the account has not been closed, has now incurred fees and is in arrears. Nedbank now tell me that the account cannot be closed due to a negative balance, despite the fact that it is their ineptitude that led to this point. I have since been assured a second time that the account was successfully closed, but this have proved to be a lie. The lack of response to emails is laughably bad, and when a response is received, the person I correspond with is so woefully incapable of dealing with the situation, refusing to even understand the the series of events which have led to this stage, and simply relying on generic emails claiming that I am in the wrong. Leaving Nedbank was one of the best decisions I have made - problem is, it is evidently actually impossible to leave them. Shocking